Class Notes
Evidence of Evolution
Questions/Main Idea:
What are the 4 main
types of evidence to
support evolution?
What are fossils?
Name: _______________________________________
Period:_______________________________________
Date: _______________________________________
Notes:
• Fossil Record
• Anatomy
• Embryology
• Biochemistry
•
Fossils → remains of ancient life
•
– Fossils arranged according to age show a progression of
changes
– The Law of Superposition → a layer of rock is older than
the layer above
• Fossils can be arranged by relative age
– Radioactive Dating → naturally occurring radioactive
substances decay at a known rate
Transitional forms of fossils are evidence for evolutionary
change
Homologous structures: parts came from the same origins, but now
may have different function
– e.g., forelimbs of all mammals contain the same pattern of
bones, although the bones now carry out a variety of
functions
• horse leg, bat wing, human arm, whale flipper
How are fossils used to
show change over time?
What is a homologous
structure?
•
How do homologous
structures support
evolution?
What is an analogous
structure?
What is a vestigial
structure?
•
•
•
Evolution works primarily by modifying pre-existing structures
Similar structures show connections between organisms, and that
they are related by an ancient common ancestor
• Analogous structures: parts came from different origin, but now
have same function
 Vestigial structures: parts have no current function (had a function
in ancestors)
– Examples in humans: wisdom teeth, erector pili, coccyx, ear
muscles, appendix
How do vestigial
structures support
evolution?
How does embryology
support evolution?
Show that our forms have changed over time.
•
•
Closely related organisms develop similarly, especially in early fetal
stages
This suggests that these organisms are related to other forms.
– Mammal embryos (including humans) have fish-like gill slits,
tails
Label the embryos with
the correct organisms’
names.
How does biochemistry
support evolution?
How is evolution
observed today?
What is the difference
between macroevolution
and microevolution?
Summary:
•
All organisms share certain biochemistry
– Genetic code for building amino acids
– All organisms use ATP for energy
– Plasma membranes of all organisms consist of a phospholipid
bi-layer
We can see microevolution in bacteria that become resistant to antibiotics;
crop pests that become resistant to pesticides and herbicides
Macroevolution = Large scale changes that take place incrementally over a
long period of time. Result in new species. Microevolution = Short time
scale events (generation-to-generation) that change the genotypes and
phenotypes of populations.